This invention relates to cathodes and more particularly to fast warmup cathodes for cathode ray tubes. Still more particularly, the cathode has application in the multiple gun structure of color cathode ray tubes. Conventional cathode ray tubes of the color variety are provided with multiple electron guns, each of which contains an electron emitting cathode. The cathodes are usually indirectly heated, that is, they comprise a tubular cathode assembly having an insulated filamentary heater contained therewithin to provide the heat necessary to cause an emissive material to emit electrons. The cathodes conventionally employed in color cathode ray tubes normally have a warmup time of 12 to 15 seconds; that is, it requires that long of a time for sufficient electrons to be present from the cathode to be drawn to the anode and establish a raster on the face plate of the picture tube. These warmup times have been considered to be detrimental to the viewing public in that it requires a long wait from turn-on to an acceptable or viewable picture on the tube. In the past, this detrimental condition had been obviated by the provision of an "instant-on" feature provided by some television receiver manufacturers. With this feature a raster on viewable picture is obtained on the picture tube almost instantaneously with the turn-on of the set; however, this feature has not in the past been accomplished by a fast warmup cathode, but rather by a bleeder current which constantly maintains the cathode heater at a near normal operating temperature. Thus in effect, the cathode ray tube is never completely turned off. When the television receiver is either a complete tube version including many receiving tubes or a hybrid version including some receiving tubes and some solid state devices, the bleeder current with the "instant-on" feature is also applied to the heaters of the other receiving tubes within the set. This condition has been alleged to provide a dangerous fire hazard in some receivers. It is also quite wasteful of electrical energy since, as mentioned above, a receiver is never completely turned off and the set is constantly drawing electrical power. It would be a decided advancement in the art if a more economical fast warmup system could be provided. Attempts have been made in the past to provide fast warmup cathodes; however, many of the proposed types have been either extremely difficult to build or have been very expensive or have required considerable design changes in the conventional electron gun structures.